400075121 has 2 divisors, whose sum is σ = 400075122. Its totient is φ = 400075120.

The previous prime is 400075079. The next prime is 400075177. The reversal of 400075121 is 121570004.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 394618225 + 5456896 = 19865^2 + 2336^2 .

It is a cyclic number.

It is not a de Polignac number, because 400075121 - 2¹⁸ = 399812977 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 400075093 and 400075102.

It is not a weakly prime, because it can be changed into another prime (400095121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200037560 + 200037561.

It is an arithmetic number, because the mean of its divisors is an integer number (200037561).

Almost surely, 2^400075121 is an apocalyptic number.

It is an amenable number.

400075121 is a deficient number, since it is larger than the sum of its proper divisors (1).

400075121 is an equidigital number, since it uses as much as digits as its factorization.

400075121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 280, while the sum is 20.

The square root of 400075121 is about 20001.8779368338. The cubic root of 400075121 is about 736.8524215293.

The spelling of 400075121 in words is "four hundred million, seventy-five thousand, one hundred twenty-one".